1. Field of the Invention
The present invention relates to a skin dullness evaluation apparatus and a skin dullness evaluation method,
2. Description of the Related Art
Skin dullness is a specific phenomenon and it is said that the skin dullness is a condition or the like that occurs at the entirety of face or a portion such as around eyes, at a cheek or the like, in which redness of skin decreases and yellowish of skin increases, in which “glow” or transparency of shin decreases, in which brightness decreases and becomes dark due to shadow by concavo-convex or the like at a skin surface. Further, it is said that a generation factor of the dullness is lowering of redness of skin color due to poor blood circulation, deposition of diffuse melanin, shadow by concavo-convex at a skin surface that occurs due to lowering of resilience of shin, lowering of transparency (optical transparency) due to thickening of skin or the like, lowering of glow due to diffusion at a skin surface, yellowing of skin in accordance with ageing or the like.
A method is known in which such skin dullness is digitized by micro concavo-convex degree of a skin surface, or skin spectrotransparency in addition to by coloring degree due to a quantity of melanin, or good, or bad in blood flow or blood circulation, for example (see Non-patent Documents 1, 2, for example).
[Patent Documents]
[Patent Document 1]Japanese Patent No. 3,798,550
[Patent Document 2]Japanese Patent No. 3,727,807
[Patent Document 3]Japanese Laid-open Patent Publication No. 2011-240086
[Non-patent Documents]
[Non-patent Document 1] Osamu Kaneko, Hiroyuki Tsukada, Yoshie Ishikawa, Yukiko Kawaguchi; J. Soc, Cosmet. Chem. Japan.; Vol. 31, No. 1 (1997)
[Non-patent Document 2] Osamu Kaneko, Yukiko Kawaguchi, Yoshie Ishikawa, Kazomasa Inagaki; J. Soc, Cosmet, Chem, Japan.; Vol. 31, No. 4 (1997)
However, the influence of color heterogeneity (unevenness of color) , that are said to be caused by redness of cheek, freckles, acne scars or the like, for example, has not been specifically considered on the definition of the above described conventional skin dullness. On the other hand, according to the research or survey conducted by the present applicant, a result was obtained that subjects who care (have) the skin dullness also care (have) color heterogeneity.